Electronic device including space-apart radiation regions and a process for forming the same

ABSTRACT

An electronic device can include a first radiation region, a second radiation region spaced apart from the first radiation region, and an insulating region. The insulating region can have a first side and a second side opposite the first side. The first radiation region can lie immediately adjacent to the first side, and the second radiation region can lie immediately adjacent to the second side. Within the insulating region, no other radiation region may lie between the first and second radiation regions, and the insulating region can include an insulating layer that includes a plurality of openings. In another aspect, a process for forming the electronic device can include patterning an insulating layer.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority under 35 U.S.C. § 119(e)from provisional U.S. Application No. 60/754,961, “Electronic DeviceIncluding Spaced-Apart Radiation Regions and a Process for Forming theSame”, MacPherson, et al, filed Dec. 27, 2005, which is incorporatedherein by reference in its entirety.

BACKGROUND INFORMATION

1. Field of the Disclosure

The disclosure relates generally to electronic devices, and morespecifically, to electronic devices including spaced-apart radiationregions and processes for forming the same.

2. Description of the Related Art

Electronic devices, including organic electronic devices, continue to bemore extensively used in everyday life. Examples of organic electronicdevice include Organic Light-Emitting Diodes (“OLEDs”). Manufacture ofsuch devices can require control over the spreading of deposited liquidcompositions. Typically, this has been accomplished by the use of anorganic or inorganic material deposited over a panel to form a bankstructure to help prevent the flow of the liquid composition intoundesirable areas. The bank could be fluorinated to improve theconfinement through an increased contact angle and reduced surfaceenergy.

Alternative methods have been used in which a receiving layer is use torapidly increase the viscosity of a deposited liquid composition, andtherefore, reduce the spreading of the liquid composition laterally andhelp to prevent overflow into neighboring pixels. The receiving layercan be formed by spin-coating material over the surface of the workpieceprior to placement of the liquid composition. The receiving layer canhelp reduce possible negative interactions between the liquidcomposition and the surface of the workpiece and may eliminate the needfor a plasma surface treatment prior to application of the liquidcomposition.

However, for resolution greater than approximately 100 pixels per squareinch, a thicker receiving layer may be required to achieve the neededcontrol in line width. An increase in receiver layer thickness couldnegatively impact both the efficiency and operating voltage of thedisplay if the receiving layer reduces the electrical, optical, or anycombination thereof, properties of the emission materials. Theuniformity of the diffusion of the deposited liquid composition into thereceiver layer can also be difficult to control and cause visualdifferences across the panel. Such visual differences can be the resultof emission of a different spectrum or intensity from portions of thepanel designed to be the same. Adjusting for these differences can use aportion of the adjustment range that could otherwise be used to extendthe usable life of the electronic component.

A different conventional process uses a vapor or solid phase diffusionprocess. Both processes suffer from similar problems previouslydescribed. If the diffusion is long enough to make the concentration ofa deposited material more uniform throughout a thickness of the layer(i.e., reduce the concentration gradient between the electrodes),lateral diffusion will be too large and can result in low resolutionbecause the pixels will need to be large. Alternatively, if lateraldiffusion can be kept at an acceptable level for high resolution, theguest material concentration gradient throughout the thickness of theorganic layer may be unacceptably large. In some instances, bothproblems may occur (i.e., unacceptably large lateral diffusion whilehaving too severe of a concentration gradient between the electrodes ofthe electronic device).

SUMMARY

An electronic device can include a first radiation region, a secondradiation region spaced apart from the first radiation region, and aninsulating region. The insulating region can have a first side and asecond side opposite the first side. The first radiation region can lieimmediately adjacent to the first side, and the second radiation regioncan lie immediately adjacent to the second side. Within the insulatingregion, no other radiation region may lie between the first and secondradiation regions, and the insulating region can include an insulatinglayer that includes a plurality of openings. In one embodiment, theelectronic device can also include a first spectral layer including afirst portion and a second portion. The first portion of the firstspectral layer can lie within the first radiation region, and the secondportion of the first spectral layer can lie within a first opening ofthe insulating layer wherein the plurality of openings includes thefirst opening. From a plan view, the first spectral layer can overlieonly a portion of the insulating layer within the insulating region.

In another aspect, a process for forming the electronic device caninclude patterning an insulating layer. The patterned insulating layercan define a plurality of openings within the insulating layer. A firstopening and a second opening of the plurality of openings can lie withinthe insulating region, wherein the insulating region having a first sideand a second side opposite the first side. A first radiation region canlie immediately adjacent to the first side, and a second radiationregion can lie immediately adjacent to the second side. Within theinsulating region, no other radiation region may lie between the firstand the second radiation regions. The process can also include forming afirst liquid composition at a first location overlying a substrate, suchthat the first liquid composition includes a first portion and a secondportion. The first portion of the first liquid composition can liewithin the first radiation region, and the second portion of the firstliquid composition can substantially fill the first opening of theplurality of openings. Substantially none of the first liquidcomposition may be formed within a second opening of the plurality ofopenings.

The foregoing general description and the following detailed descriptionare exemplary and explanatory only and are not restrictive of theinvention, as defined in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is illustrated by way of example and not limitation in theaccompanying figures.

FIG. 1 includes an illustration of a cross-sectional view of a workpieceincluding a substrate, first electrodes, and an insulating layer.

FIG. 2 includes an illustration of an enlarged cross-sectional view of aportion of the workpiece of FIG. 1 after forming a plurality of openingsin the insulating layer and before removing the masking layer.

FIGS. 3 and 4 include illustrations of cross-sectional views of theworkpiece of FIGS. 1 and 2 after forming a portion of an organic layer.

FIGS. 5 and 6 include illustrations of cross-sectional views of theworkpiece of FIGS. 3 and 4 after forming an optional portion of theorganic layer.

FIGS. 7 and 8 include illustrations of cross-sectional views of aportion of the workpiece after forming an organic active layer.

FIG. 9 includes an illustration of a top view of the workpiece of FIG.7.

FIG. 10 includes an illustration of a cross-sectional view of a portionof a substantially completed electronic device.

FIG. 11 includes an illustration of a top view of a portion of aworkpiece according to an alternative embodiment, wherein a portion ofthe insulating layer overlying first electrodes 14 and 16 has beenremoved.

FIG. 12 includes an illustration of a top view of a portion of theworkpiece according to an alternative embodiment, wherein channels areformed between some of the openings along the path of a subsequentcontinuous printing process.

FIG. 13 includes an illustration of a cross-sectional view of a portionof the workpiece according to an alternative embodiment, wherein theplurality of openings is formed prior to formation of the firstelectrode.

FIG. 14 includes an illustration of a top view of a surface with tworegions according to an alternative embodiment.

FIG. 15 includes an illustration of a top view of a surface including anedge of a continuously printed feature aligned to edges of openings indifferent rows of an array of openings.

FIG. 16 includes an illustration of a top view of an example of acontinuously printed line overlying a region containing a plurality ofopenings.

Skilled artisans appreciate that elements in the figures are illustratedfor simplicity and clarity and have not necessarily been drawn to scale.For example, the dimensions of some of the elements in the figures maybe exaggerated relative to other elements to help to improveunderstanding of embodiments of the invention.

DETAILED DESCRIPTION

In a first aspect, an electronic device can include a first radiationregion, a second radiation region spaced apart from the first radiationregion, and an insulating region. The insulating region can have a firstside and a second side opposite the first side. The first radiationregion can lie immediately adjacent to the first side, and the secondradiation region can lie immediately adjacent to the second side. Withinthe insulating region, no other radiation region may lie between thefirst and second radiation regions, and the insulating region caninclude an insulating layer that includes a plurality of openings. Theelectronic device can also include a first spectral layer including afirst portion and a second portion. The first portion of the firstspectral layer can lie within the first radiation region, and the secondportion of the first spectral layer lies within a first opening of theinsulating layer, wherein the plurality of openings includes the firstopening. From a plan view, the first spectral layer can overlie only aportion of the insulating layer within the insulating region.

In one embodiment of the first aspect, the plurality of openings forms aregular pattern. In another embodiment, each opening within theplurality of openings includes substantially a same size, a same shape,or any combination thereof.

In still another embodiment of the first aspect, the first radiationregion further includes a portion of the insulating layer. In aparticular embodiment, within the first radiation region, at least apart of the first portion of the first spectral layer lies within asecond opening of the plurality of openings. In a more particularembodiment, the first radiation region further includes a conductivemember overlying the insulating layer. In another more particularembodiment, the first radiation region further includes a conductivemember, and wherein the insulating layer overlies the conductive member.

In yet another embodiment of the first aspect, a third opening of theplurality of openings includes a channel. In a particular embodiment,from a plan view, the channel changes direction at least once along alength of the channel. In another embodiment, the first spectral layerincludes an organic active layer. In still another embodiment, theelectronic device can further include a second spectral layer includinga first portion and a second portion. The first portion of the secondspectral layer lies within the second radiation region. The secondportion of the second spectral layer lies within a second opening of theinsulating layer, wherein the plurality of openings includes the secondopening. From a plan view, the second spectral layer overlies only aportion of the insulating layer within the insulating region. In yetanother embodiment, the insulating layer includes an oxide, a nitride,or any combination thereof.

In a second aspect, a process for forming an electronic device caninclude patterning an insulating layer. The patterned insulating layercan define a plurality of openings within the insulating layer. A firstopening and a second opening of the plurality of openings can lie withinthe insulating region, the insulating region having a first side and asecond side opposite the first side. A first radiation region can lieimmediately adjacent to the first side, and a second radiation regioncan lie immediately adjacent to the second side. Within the insulatingregion, no other radiation region may lie between the first and thesecond radiation regions. The process can also include forming a firstliquid composition at a first location overlying a substrate, whereinthe first liquid composition can include a first portion and a secondportion. The first portion of the first liquid composition can liewithin the first radiation region, and the second portion of the firstliquid composition can substantially fill the first opening of theplurality of openings. Substantially none of the first liquidcomposition may be formed within the second opening of the plurality ofopenings.

In one embodiment of the second aspect, during formation of the firstliquid composition, a thickness of the first liquid composition layer isat least four times a depth of the first opening. In another embodiment,the process can further include forming a second liquid composition at asecond location overlying the substrate, such that the second liquidcomposition substantially fills a third opening of the plurality ofopenings. In a particular embodiment, a portion of the patternedinsulating layer including the second opening lies between the firstlocation and the second location. In a more particular embodiment,substantially none of the second liquid composition is formed within thesecond opening.

In another embodiment of the second aspect, forming the first liquidcomposition includes continuously printing the first liquid composition.In a particular embodiment, the first liquid composition includes aspectral material. In another embodiment, patterning the insulatinglayer further includes forming at least one opening extending throughthe insulating layer.

Many aspects and embodiments have been described above and are merelyexemplary and not limiting. After reading this specification, skilledartisans appreciate that other aspects and embodiments are possiblewithout departing from the scope of the invention.

Other features and advantages of the invention will be apparent from thefollowing detailed description, and from the claims. The detaileddescription first addresses Definitions and Clarification of Termsfollowed by Liquid Compositions, Fabrication Before Organic Active LayerFormation, Formation of Organic Layer(s), Remainder of Fabrication,Alternative Embodiments, Advantages, and finally Examples.

1. Definitions and Clarification of Terms

Before addressing details of embodiments described below, some terms aredefined or clarified. The terms “array,” “peripheral circuitry,” and“remote circuitry” are intended to mean different areas or components ofan electronic device. For example, an array may include pixels, cells,or other structures within an orderly arrangement (usually designated bycolumns and rows). The pixels, cells, or other structures within thearray may be controlled by peripheral circuitry, which may lie on thesame substrate as the array but outside the array itself. Remotecircuitry typically lies away from the peripheral circuitry and can sendsignals to or receive signals from the array (typically via theperipheral circuitry). The remote circuitry may also perform functionsunrelated to the array. The remote circuitry may or may not reside onthe substrate having the array.

The term “channel” when referring to an opening is intended to mean suchopening has a length that is significantly greater than its width.

The term “change direction,” when referring to a channel, is intended tomean that along a length of the channel, which is a line defined by thecenter of the width of the channel, is not a straight line.

The term “conductive,” when referring to a layer, material, member, orstructure, is intended to mean such layer, material, member, orstructure is not insulating.

The term “continuous” and its variants are intended to meansubstantially unbroken. In one embodiment, continuously printing isprinting using a substantially unbroken stream of a liquid or a liquidcomposition, as opposed to a depositing technique using drops. Inanother embodiment, extending continuously refers to a length of alayer, member, or structure in which no significant breaks in the layer,member, or structure lie along its length.

The term “electronic component” is intended to mean a lowest level unitof a circuit that performs an electrical or electro-radiative (e.g.,electro-optic) function. An electronic component may include atransistor, a diode, a resistor, a capacitor, an inductor, asemiconductor laser, an optical switch, or the like. An electroniccomponent does not include parasitic resistance (e.g., resistance of awire) or parasitic capacitance (e.g., capacitive coupling between twoconductors electrically connected to different electronic componentswhere a capacitor between the conductors is unintended or incidental).

The term “electronic device” is intended to mean a collection ofcircuits, electronic components, or combinations thereof thatcollectively, when properly electrically connected and supplied with theappropriate potential(s), performs a function. An electronic device mayinclude or be part of a system. An example of an electronic deviceincludes a display, a sensor array, a computer system, an avionicssystem, an automobile, a cellular phone, other consumer or industrialelectronic product, or any combination thereof.

The term “elevation” is intended to mean a distance from a primarysurface of a substrate as measured in a direction perpendicular to theprimary surface.

The term “hole” is intended to mean a penetration into a surface, asformed by a removal process. A hole may extend partially or completelythrough a layer of substrate.

The term “insulating” and its variants are intended to mean a layer,material, member, or structure having an electrical property such that(1) it has a significant associated voltage drop across or through suchlayer, material, member, or structure or (2) it substantially prevents asignificant number of charge carriers from flowing through suchmaterial, layer, member or structure. For example, an insulatingmaterial has a bulk resistivity no lower than 10⁻² ohm-cm.

The term “layer” is intended to mean a substrate or a film overlying asubstrate.

The term “liquid composition” is intended to mean a liquid medium inwhich a material is dissolved to form a solution, a liquid medium inwhich a material is dispersed to form a dispersion, or a liquid mediumin which a material is suspended to form a suspension or an emulsion.

The term “liquid medium” is intended to mean a liquid material,including a pure liquid, a combination of liquids, a solution, adispersion, a suspension, and an emulsion. Liquid medium is usedregardless whether one or more solvents are present.

The term “opening” is intended to mean a depression in the workpiecesurface corresponding to a hole at a particular point in the fabricationprocess. When a hole is first formed, an opening and a hole are thesame. A layer may partially, but not completely fill a hole. The holedoes not change, but the remaining portion of the hole that is notoccupied by the layer is now the opening.

The term “organic active layer” is intended to mean one or more organiclayers, wherein at least one of the organic layers, by itself, or whenin contact with a dissimilar material is capable of forming a rectifyingjunction.

The term “organic layer” is intended to mean one or more layers, whereinat least one of the insulating layers comprises a material includingcarbon and at least one other element, such as hydrogen, oxygen,nitrogen, fluorine, etc.

The term “pixel” is intended to mean the smallest complete, repeatingunit of an array. The term “subpixel” is intended to mean a portion of apixel that makes up only a part, but not all, of a pixel. In afull-color display, a full-color pixel can comprise three sub-pixelswith primary colors in red, green and blue spectral regions. Amonochromatic display may include pixels but no subpixels. A sensorarray can include pixels that may or may not include subpixels.

The term “primary surface” is intended to mean a surface of a substratefrom which an electronic component is subsequently formed.

The term “radiation-emitting component” is intended to mean anelectronic component, which when properly biased, emits radiation at atargeted wavelength or spectrum of wavelengths. The radiation may bewithin the visible-light spectrum or outside the visible-light spectrum(UV or IR). A light-emitting diode is an example of a radiation-emittingcomponent.

The term “radiation region” is intended to mean a region that includes aradiation-emitting component, a radiation-responsive component, or alayer, member, or structure that changes the quality of radiationpassing through such layer, member, or structure (e.g., a radiationfilter layer). The radiation may be within the visible-light spectrum oroutside the visible-light spectrum (UV or IR). A radiation region cancorrespond to a pixel or sub-pixel of an electronic device.

The term “radiation-responsive component” is intended to mean anelectronic component, which when properly biased, can respond toradiation at a targeted wavelength or spectrum of wavelengths. Theradiation may be within the visible-light spectrum or outside thevisible-light spectrum (UV or IR). An IR sensor and a photovoltaic cellare examples of radiation-sensing components.

The term “rectifying junction” is intended to mean a junction within asemiconductor layer or a junction formed by an interface between asemiconductor layer and a dissimilar material, in which charge carriersof one type flow easier in one direction through the junction comparedto the opposite direction. A p-n junction is an example of a rectifyingjunction that can be used as a diode.

The term “regular pattern” is intended to mean an orderly arrangement offeatures and spaces between the features, wherein along at least onedirection, each of the features are substantially the same size andshape and the spaces between the features are substantially the samedistance. In one embodiment, the regular pattern may extend in more thanone direction, such as along a vertical direction and a horizontaldirection, along different diagonal directions, or any combinationthereof.

The term “spectral,” with respect to a layer or material, is intended tomean that such layer or material can emit, respond to, or filterradiation at a targeted wavelength or spectrum of wavelengths.

The term “spectrum” is intended to mean more than one wavelength.Spectrum can correspond to one or more ranges of wavelengths. The rangescan be contiguous, overlapping, spaced apart, or any combinationthereof.

The term “substrate” is intended to mean a base material that can beeither rigid or flexible and may include one or more layers of one ormore materials, which can include, but are not limited to, glass,polymer, metal or ceramic materials or combinations thereof. Thereference point for a substrate is the beginning point of a processsequence. The substrate may or may not include electronic components,circuits, or conductive members. The term “user surface” is intended tomean a surface of the electronic device principally used during normaloperation of the electronic device. In the case of a display, thesurface of the electronic device seen by a user would be a user surface.In the case of a sensor or photovoltaic cell, the user surface would bethe surface that principally transmits radiation that is to be sensed orconverted to electrical energy. Note that an electronic device may havemore than one user surface.

The term “visible light spectrum” is intended to mean a radiationspectrum having wavelengths corresponding to 400 to 700 nm.

The term “workpiece” is intended to mean a substrate, or if one or morelayers, members, or structures are present, a combination of suchsubstrate and such one or more layers, members, or structures at anyparticular point of a process sequence. Note that the substrate may notsignificantly change during a process sequence, whereas the workpiecesignificantly changes during the process sequence. For example, at abeginning of a process sequence, the substrate and workpiece are thesame. After a layer is formed over the substrate, the substrate has notchanged, but now the workpiece includes the substrate and the layer.

As used herein, the terms “comprises,” “comprising,” “includes,”“including,” “has,” “having” or any other variation thereof, areintended to cover a non-exclusive inclusion. For example, a process,method, article, or apparatus that comprises a list of elements is notnecessarily limited to only those elements but may include otherelements not expressly listed or inherent to such process, method,article, or apparatus. Further, unless expressly stated to the contrary,“or” refers to an inclusive or and not to an exclusive or. For example,a condition A or B is satisfied by any one of the following: A is true(or present) and B is false (or not present), A is false (or notpresent) and B is true (or present), and both A and B are true (orpresent).

Additionally, for clarity purposes and to give a general sense of thescope of the embodiments described herein, the use of the “a” or “an”are employed to describe one or more articles to which “a” or “an”refers. Therefore, the description should be read to include one or atleast one whenever “a” or “an” is used, and the singular also includesthe plural unless it is clear that the contrary is meant otherwise.Group numbers corresponding to columns within the periodic table of theelements use the “New Notation” convention as seen in the CRC Handbookof Chemistry and Physics, 81^(st) Edition (2000).

Unless otherwise defined, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this invention belongs. Although suitable methods andmaterials are described herein for embodiments of the invention, ormethods for making or using the same, other methods and materialssimilar or equivalent to those described can be used without departingfrom the scope of the invention. All publications, patent applications,patents, and other references mentioned herein are incorporated byreference in their entirety. In case of conflict, the presentspecification, including definitions, will control. In addition, thematerials, methods, and examples are illustrative only and not intendedto be limiting.

Other features and advantages of the invention will be apparent from thefollowing detailed description, and from the claims.

To the extent not described herein, many details regarding specificmaterials, processing acts, and circuits are conventional and may befound in textbooks and other sources within the organic light-emittingdiode display, photodetector, photovoltaic, and semiconductor arts.

2. Liquid Compositions

Liquid compositions, continuous printing apparatuses, and methods ofusing liquid compositions and continuous printing apparatuses aredescribed in more detail in U.S. patent application Ser. No. 11/027,133,entitled “Electronic Devices and Processes For Forming the Same” byMacPherson et al., filed on Dec. 30, 2004. In addition to continuousprinting apparatuses, other apparatuses, such as ink jet printers, spincoaters, etc. can be used to deposit or otherwise form liquidcompositions over substrates.

The liquid composition can be in the form of a solution, dispersion,emulsion, or suspension. In the paragraphs that follow, non-limitingexamples of solid materials and liquid medium are given. The solidmaterial(s) can be selected based upon the electronic orelectro-radiative properties for a subsequently formed layer. The liquidmedium can be selected based on criteria described later in thisspecification.

An organic layer printed using a printing apparatus (e.g., an ink-jetprinting apparatus, a continuous printing apparatus, another suitableselective liquid depositing apparatus, or any combination thereof caninclude an organic active layer (e.g., a radiation-emitting organicactive layer or a radiation-responsive organic active layer), filterlayer, buffer layer, charge-injecting layer, charge-transport layer,charge-blocking layer, or any combination thereof. The organic layer maybe used as part of a resistor, transistor, capacitor, diode, etc.

For a radiation-emitting organic active layer, suitableradiation-emitting materials include one or more small moleculematerials, one or more polymeric materials, or a combination thereof. Asmall molecule material may include any one or more of those describedin, for example, U.S. Pat. No. 4,356,429 (“Tang”); U.S. Pat. No.4,539,507 (“Van Slyke”); U.S. Patent Application Publication No. US2002/0121638 (“Grushin”); or U.S. Pat. No. 6,459,199 (“Kido”).Alternatively, a polymeric material may include any one or more of thosedescribed in U.S. Pat. No. 5,247,190 (“Friend”); U.S. Pat. No. 5,408,109(“Heeger”); or U.S. Pat. No. 5,317,169 (“Nakano”). An exemplary materialis a semiconducting conjugated polymer. An example of such a polymerincludes poly(paraphenylenevinylene) (PPV), a PPV copolymer, apolyfluorene, a polyphenylene, a polyacetylene, a polyalkylthiophene,poly(n-vinylcarbazole) (PVK), or the like. For a radiation-responsiveorganic active layer, a suitable radiation-responsive material mayinclude many a conjugated polymer or an electroluminescent material.Such a material includes, for example, a conjugated polymer or anelectro- and photo-luminescent material. A specific example includespoly(2-methoxy,5-(2-ethyl-hexyloxy)-1,4-phenylene vinylene) (“MEH-PPV”)or a MEH-PPV composite with CN-PPV.

The location of a filter layer may be between an organic active layerand a user side of the electronic device. A filter layer may be part ofa substrate, an electrode (e.g., an anode or a cathode), acharge-transport layer, a charge-injecting layer, a charge-blockinglayer; the filter layer may lie between any one or more of thesubstrate, an electrode, a charge-transport layer, a charge-injectinglayer, a charge-blocking layer, or any combination thereof. In anotherembodiment, the filter layer may be a layer that is fabricatedseparately (while not attached to the substrate) and later attached tothe substrate at any time before, during, or after fabricating theelectronic components within the electronic device. In this embodiment,the filter layer may lie between the substrate and a user of theelectronic device.

When the filter layer is separate from or part of the substrate, or whenthe filter lies between the substrate and an electrode closest to thesubstrate, a suitable material includes an organic material including apolyolefin (e.g., polyethylene or polypropylene); a polyester (e.g.,polyethylene terephthalate or polyethylene naphthalate); a polyimide; apolyamide; a polyacrylonitrile or a polymethacrylonitrile; aperfluorinated or partially fluorinated polymer (e.g.,polytetrafluoroethylene or a copolymer of tetrafluoroethylene andpolystyrene); a polycarbonate; a polyvinyl chloride; a polyurethane; apolyacrylic resin, including a homopolymer or a copolymer of an ester ofan acrylic or methacrylic acid; an epoxy resin; a Novolac resin; or anycombination thereof.

For a hole-injecting layer, hole-transport layer, electron-blockinglayer, or any combination thereof, a suitable material includespolyaniline (“PANI”), poly(3,4-ethylenedioxythiophene) (“PEDOT”),polypyrrole, an organic charge transfer compound, such astetrathiafulvalene tetracyanoquinodimethane (“TTF-TCQN”), ahole-transport material as described in Kido, or any combinationthereof.

For an electron-injecting layer, electron transport layer, hole-blockinglayer, or any combination thereof, a suitable material includes ametal-chelated oxinoid compound (e.g., tris-(8-hydroxyquinoline)aluminum (“Alq₃”),bis-(2-methyl-8-quinolate)4-(phenylphenolato)-aluminum (“BAlq”),zirconium 8-hydroxyquinoline (“Zrq₄”)); a phenanthroline-based compound(e.g., 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (“DDPA”) or9,10-diphenylanthracence (“DPA”)); an azole compound (e.g.,2-tert-butylphenyl-5-biphenyl-1,3,4-oxadiazole (“PBD”) or3-(4-biphenyl)-4-phenyl-5-(4-t-butylphenyl)-1,2,4-triazole (“TAZ”); anelectron transport material as described in Kido; a diphenylanthracenederivative; a dinaphthylanthracene derivative;4,4-bis(2,2-diphenyl-ethen-1-yl)-biphenyl (“DPVBI”);9,10-di-beta-naphthylanthracene; 9,10-di-(naphenthyl)anthracene;9,10-di-(2-naphthyl)anthracene (“ADN”); 4,4′-bis(carbazol-9-yl)biphenyl(“CBP”); 9,10-bis-[4-(2,2-diphenylvinyl)-phenyl]-anthracene (“BDPVPA”);anthracene, N-arylbenzimidazoles (such as “TPBI”);1,4-bis[2-(9-ethyl-3-carbazoyl)vinylenyl]benzene;4,4′-bis[2-(9-ethyl-3-carbazoyl)vinylenyl]-1,1′-biphenyl;9,10-bis[2,2-(9,9-fluorenylene)vinylenyl]anthracene;1,4-bis[2,2-(9,9-fluorenylene)vinylenyl]benzene;4,4′-bis[2,2-(9,9-fluorenylene)vinylenyl]-1,1′-biphenyl; perylene,substituted perylenes; tetra-tert-butylperylene (“TBPe”);bis(3,5-difluoro-2-(2-pyridyl)phenyl-(2-carboxypyridyl)) iridium III(“F(Ir)Pic”); a pyrene, a substituted pyrene; a styrylamine; afluorinated phenylene; oxidazole;1,8-naphthalimide; a polyquinoline; oneor more carbon nanotubes within PPV; or any combination thereof.

For an electronic component, such as a resistor, transistor, capacitor,etc., the organic layer may include one or more of thiophenes (e.g.,polythiophene, poly(alkylthiophene), alkylthiophene,bis(dithienthiophene), alkylanthradithiophene, etc.), polyacetylene,pentacene, phthalocyanine, or any combination thereof.

An example of an organic dye includes4-dicyanmethylene-2-methyl-6-(p-dimethyaminostyryl)-4H-pyran (DCM),coumarin, pyrene, perylene, rubrene, a derivative thereof, or anycombination thereof.

An example of an organometallic material includes a functionalizedpolymer comprising one or more functional groups coordinated to at leastone metal. An exemplary functional group contemplated for use includes acarboxylic acid, a carboxylic acid salt, a sulfonic acid group, asulfonic acid salt, a group having an OH moiety, an amine, an imine, adiimine, an N-oxide, a phosphine, a phosphine oxide, a β-dicarbonylgroup, or any combination thereof. An exemplary metal contemplated foruse includes a lanthanide metal (e.g., Eu, Tb), a Group 7 metal (e.g.,Re), a Group 8 metal (e.g., Ru, Os), a Group 9 metal (e.g., Rh, Ir), aGroup 10 metal (e.g., Pd, Pt), a Group 11 metal (e.g., Au), a Group 12metal (e.g., Zn), a Group 13 metal (e.g., Al), or any combinationthereof. Such an organometallic material includes a metal chelatedoxinoid compound, such as tris(8-hydroxyquinolato)aluminum (Alq₃); acyclometalated iridium or platinum electroluminescent compound, such asa complex of iridium with phenylpyridine, phenylquinoline, orphenylpyrimidine ligands as disclosed in published PCT Application WO02/02714, an organometallic complex described in, for example, publishedapplications US 2001/0019782, EP 1191612, WO 02/15645, WO 02/31896, andEP 1191614; or any mixture thereof.

An example of a conjugated polymer includes a poly(phenylenevinylene), apolyfluorene, a poly(spirobifluorene), a copolymer thereof, or anycombination thereof.

Selecting a liquid medium can also be an important factor for achievingone or more proper characteristics of the liquid composition. A factorto be considered when choosing a liquid medium includes, for example,viscosity of the resulting solution, emulsion, suspension, ordispersion, molecular weight of a polymeric material, solids loading,type of liquid medium, boiling point of the liquid medium, temperatureof an underlying substrate, thickness of an organic layer, or anycombination thereof.

In some embodiments, the liquid medium includes at least one solvent. Anexemplary organic solvent includes a halogenated solvent, acolloidal-forming polymeric acid, a hydrocarbon solvent, an aromatichydrocarbon solvent, an ether solvent, a cyclic ether solvent, analcohol solvent, a glycol solvent, a ketone solvent, a nitrile solvent,a sulfoxide solvent, an amide solvent, an ester solvent, or anycombination thereof.

An exemplary halogenated solvent includes carbon tetrachloride,methylene chloride, chloroform, tetrachloroethylene, chlorobenzene,bis(2-chloroethyl)ether, chloromethyl ethyl ether, chloromethyl methylether, 2-chloroethyl ethyl ether, 2-chloroethyl propyl ether,2-chloroethyl methyl ether, or any combination thereof.

An exemplary colloid-forming polymeric acid includes a fluorinatedsulfonic acid (e.g., fluorinated alkylsulfonic acid, such asperfluorinated ethylenesulfonic acid) or any combinations thereof.

An exemplary hydrocarbon solvent includes pentane, hexane, cyclohexane,heptane, octane, decahydronaphthalene, a petroleum ether, ligroine, orany combination thereof.

An exemplary aromatic hydrocarbon solvent includes benzene, naphthalene,toluene, xylene, ethyl benzene, diethyl benzene, cumene (iso-propylbenzene), mesitylene (trimethyl benzene), ethyl toluene, butyl benzene,cymene (iso-propyl toluene), diethylbenzene, iso-butyl benzene,tetramethyl benzene, sec-butyl benzene, tert-butyl benzene, anisole,4-methylanisole, 3,4-dimethylanisole, decyl benzene, another alkylbenzene, or any combination thereof.

An exemplary ether solvent includes diethyl ether, ethyl propyl ether,dipropyl ether, diisopropyl ether, dibutyl ether, methyl t-butyl ether,glyme, diglyme, benzyl methyl ether, isochroman, 2-phenylethyl methylether, n-butyl ethyl ether, 1,2-diethoxyethane, sec-butyl ether,diisobutyl ether, ethyl n-propyl ether, ethyl isopropyl ether, n-hexylmethyl ether, n-butyl methyl ether, methyl n-propyl ether, or anycombination thereof.

An exemplary cyclic ether solvent includes tetrahydrofuran, dioxane,tetrahydropyran, 4 methyl-1,3-dioxane, 4-phenyl-1,3-dioxane,1,3-dioxolane, 2-methyl-1,3-dioxolane, 1,4-dioxane, 1,3-dioxane,2,5-dimethoxytetrahydrofuran, 2,5-dimethoxy-2,5-dihydrofuran, or anycombination thereof.

An exemplary alcohol solvent includes methanol, ethanol, 1-propanol,2-propanol, 1-butanol, 2-butanol, 2-methyl-1-propanol (i.e.,iso-butanol), 2-methyl-2-propanol (i.e., tert-butanol), 1-pentanol,2-pentanol, 3-pentanol, 2,2-dimethyl-1-propanol, 1-hexanol,cyclopentanol, 3-methyl-1-butanol, 3-methyl-2-butanol,2-methyl-1-butanol, 2,2-dimethyl-1-propanol, 3-hexanol, 2-hexanol,4-methyl-2-pentanol, 2-methyl-1-pentanol, 2-ethylbutanol,2,4-dimethyl-3-pentanol, 3-heptanol, 4-heptanol, 2-heptanol, 1-heptanol,2-ethyl-1-hexanol, 2,6-dimethyl-4-heptanol, 2-methylcyclohexanol,3-methylcyclohexanol, 4-methylcyclohexanol, or any combination thereof.

An alcohol ether solvent may also be employed. An exemplary alcoholether solvent includes 1-methoxy-2-propanol, 2-methoxyethanol,2-ethoxyethanol, 1-methoxy-2-butanol, ethylene glycol monoisopropylether, 1-ethoxy-2-propanol, 3-methoxy-1-butanol, ethylene glycolmonoisobutyl ether, ethylene glycol mono-n-butyl ether,3-methoxy-3-methylbutanol, ethylene glycol mono-tert-butyl ether, or anycombination thereof.

An exemplary glycol solvent includes ethylene glycol, propylene glycol,propylene glycol monomethyl ether (PGME), dipropylene glycol monomethylether (DPGME), or any combination thereof.

An exemplary ketone solvent includes acetone, methylethyl ketone, methyliso-butyl ketone, cyclohexanone, diethyl ketone, isopropyl methylketone, 2-pentanone, 3-pentanone, 3-hexanone, diisopropyl ketone,2-hexanone, cyclopentanone, 4-heptanone, iso-amyl methyl ketone,3-heptanone, 2-heptanone, 4-methoxy-4-methyl-2-pentanone,5-methyl-3-heptanone, 2-methylcyclohexanone, diisobutyl ketone,5-methyl-2-octanone, 3-methylcyclohexanone, 2-cyclohexen-1-one,4-methylcyclohexanone, cycloheptanone, 4-tert-butylcyclohexanone,isophorone, benzyl acetone, or any combination thereof.

An exemplary nitrile solvent includes acetonitrile, acrylonitrile,trichloroacetonitrile, propionitrile, pivalonitrile, isobutyronitrile,n-butyronitrile, methoxyacetonitrile, 2-methylbutyronitrile,isovaleronitrile, N-valeronitrile, n-capronitrile,3-methoxypropionitrile, 3-ethoxypropionitrile, 3,3′-oxydipropionitrile,n-heptanenitrile, glycolonitrile, benzonitrile, ethylene cyanohydrin,succinonitrile, acetone cyanohydrin, 3-n-butoxypropionitrile, or anycombination thereof.

An exemplary sulfoxide solvent includes dimethyl sulfoxide, di-n-butylsulfoxide, tetramethylene sulfoxide, methyl phenyl sulfoxide, or anycombinations thereof.

An exemplary amide solvent includes dimethyl formamide, dimethylacetamide, acylamide, 2-acetamidoethanol, N,N-dimethyl-m-toluamide,trifluoroacetamide, N,N-dimethylacetamide, N,N-diethyldodecanamide,epsilon-caprolactam, N,N-diethylacetamide, N-tert-butylformamide,formamide, pivalamide, N-butyramide, N,N-dimethylacetoacetamide,N-methyl formamide, N,N-diethylformamide, N-formylethylamine, acetamide,N,N-diisopropylformamide, 1-formylpiperidine, N-methylformanilide, orany combinations thereof.

Ester solvents can include alkyl esters of short chain carboxylic acids,alkyl esters of glycols, benzyl esters, di-ester solvents, dibasicesters, phenyl diesters, or any combination thereof. An exemplary estersolvent includes benzyl benzoate, butyl benzoate, dibutyl phthalate,dimethyl phthalate, dimethyl suberate, ethyl acetate, ethylene glycoldiacetate, isobutyl acetate, isobutyl isobutyrate, methyl benzoate, orany combinations thereof.

A crown ether contemplated includes any one or more crown ethers thatcan function to assist in the reduction of the chloride content of anepoxy compound starting material as part of the combination beingtreated according to the invention. An exemplary crown ether includesbenzo-15-crown-5; benzo-18-crown-6; 12-crown-4; 15-crown-5; 18-crown-6;cyclohexano-15-crown-5; 4′,4″(5″)-ditert-butyldibenzo-18-crown-6;4′,4″(5″)-ditert-butyld icyclohexano-18-crown-6;dicyclohexano-18-crown-6; dicyclohexano-24-crown-8;4′-aminobenzo-15-crown-5; 4′-aminobenzo-18-crown-6;2-(aminomethyl)-15-crown-5; 2-(aminomethyl)-18-crown-6;4′-amino-5′-nitrobenzo-15-crown-5; 1-aza-12-crown-4; 1-aza-15-crown-5;1-aza-18-crown-6; benzo-12-crown-4; benzo-15-crown-5; benzo-18-crown-6;bis((benzo-15-crown-5)-15-ylmethyl)pimelate; 4-bromobenzo-18-crown-6;(+)−(18-crown-6)-2,3,11,12-tetra-carboxylic acid; dibenzo-18-crown-6;dibenzo-24-crown-8; dibenzo-30-crown-10;ar-ar′-di-tert-butyldibenzo-18-crown-6; 4′-formylbenzo-15-crown-5;2-(hydroxymethyl)-12-crown-4; 2-(hydroxymethyl)-15-crown-5;2-(hydroxymethyl)-18-crown-6; 4′-nitrobenzo-15-crown-5;poly-[(dibenzo-18-crown-6)-co-formaldehyde];1,1-dimethylsila-11-crown-4; 1,1-dimethylsila-14-crown-5;1,1-dimethylsila-17-crown-5; cyclam;1,4,10,13-tetrathia-7,16-diazacyclooctadecane; porphines; or anycombinations thereof.

Skilled artisans will appreciate that some derivatives of the abovementioned solvents can also be used. For example, a halogen can besubstituted for a hydrogen at a location of an above mentioned solvent,and the resulting chemical can still exhibit solvent properties.

In another embodiment, the liquid medium includes water. A conductivepolymer complexed with a water-insoluble colloid-forming polymeric acidcan be deposited over a substrate and used as a charge-transport layer.

Many different classes of liquid media (e.g., halogenated solvents,hydrocarbon solvents, aromatic hydrocarbon solvents, water, etc.) aredescribed above. Mixtures of more than one example of a liquid mediumfrom different classes may also be used.

The liquid composition may also include an inert material, such as abinder material, a filler material, or a combination thereof. Withrespect to the liquid composition, an inert material does notsignificantly affect the electronic, radiation emitting, or radiationresponding properties of a layer that is formed by or receives at leasta portion of the liquid composition.

3. Fabrication Before Organic Active Layer Formation

FIG. 1 includes an illustration of a cross-sectional view of a portionof a workpiece 10 after forming an insulating layer 18 over a substrate12 of an insulating region 112, a first electrode 14 of a radiationregion 114, and a first electrode 16 of a radiation region 116. Thesubstrate 12 can be either rigid or flexible and may include one or morelayers of one or more materials, which can include, but are not limitedto, glass, polymer, metal or ceramic materials or combinations thereof.In one embodiment, the substrate 12 is substantially transparent to atargeted wavelength or spectrum of wavelengths associated with theelectronic device. For example, the electronic device may emit radiationwithin the visible light spectrum, and thus, the substrate 12 would betransparent to radiation within the visible light spectrum. In anotherexample, the electronic device may respond to infrared radiation, andthus the substrate 12 would be transparent to the infrared radiation.The substrate 12 can have a thickness in a range of from approximately12 to approximately 2500 microns.

The substrate 12 includes a primary surface 110. The primary surface 110can be a surface from which at least some of the electronic componentsfor the electronic device may be fabricated. Although not illustrated,control circuits may lie within the substrate 12, wherein each controlcircuit would be electrically connected to a corresponding firstelectrode such as the first electrode 14 or 16. The electronic devicecan also have a user surface 118, which can be the surface of theelectronic device seen by a user when using the electronic device, asdesigned.

First electrodes 14 and 16 are formed over the substrate 12, asillustrated in FIG. 1. In one embodiment, each of the first electrodes14 and 16 can act as an anode for an electronic component, and thusincludes one or more layers used as anodes within LCD or OLED displays.First electrodes 14 and 16 can be formed by a deposition using aconventional or proprietary technique. The first electrodes 14 and 16may have a thickness in a range of approximately 10 nm to approximately1000 nm. Other first electrodes for other electronic components areformed but are not illustrated in FIG. 1.

FIG. 1 includes the radiation region 114 and the radiation region 116.The radiation region 114 has sides that are substantially coterminouswith sides of the first electrode 14 and extend in directionssubstantially perpendicular to the user surface 118. The radiationregion 116 has sides that are substantially coterminous with sides ofthe first electrode 16 and extend in directions substantiallyperpendicular to the user surface 118. The insulating region 112 can liebetween the radiation regions 114 and 116 with no other radiation regionlying between the radiation regions 114 and 116. The insulating region112 can have first and second opposing sides that lie immediatelyadjacent to the radiation regions 114 and 116, respectively.

In the embodiment as illustrated in FIG. 1, an insulating layer 18 canbe formed over the workpiece 10. The insulating layer 18 can be anoxide, a nitride, an oxynitride, or any combination thereof. In oneparticular embodiment, if thermal conduction is needed or desired, theinsulating layer 18 can include AIN or an epoxy resin (e.g., FR4). Thethickness of the insulating layer 18 can be in a range of approximately50 nm to approximately 1000 nm, and in a particular embodiment can be ina range of approximately 100 nm to approximately 400 nm. In anotherembodiment, the insulating layer 18 can be approximately one-third thethickness of the electrode 14. The insulating layer 18 can be formed bya conventional or proprietary technique.

FIG. 2 illustrates the workpiece 10 of FIG. 1 after forming a patternedlayer 22. FIG. 2 includes an enlarged portion of the workpiece 10 at aregion as illustrated by the dashed circle 2 in FIG. 1. The patternedlayer 22 is formed over workpiece 10 by one or more conventional orproprietary lithographic techniques. Exposed portions of the insulatinglayer 18 are then removed to form a plurality of openings in theinsulating layer 18. In one embodiment an opening of the plurality ofopenings can extend through the insulating layer 18. In otherembodiments, the opening of the plurality of openings may extend onlypartially through the insulating layer 18 and have a depth in a range ofapproximately 50 nm to approximately 1000 nm, and in a particularembodiment can be in a range of approximately 100 nm to approximately400 nm. The plurality of openings described with respect to layer 18 isalso a plurality of holes at this point in the process.

An opening of the plurality of openings can be within the insulatingregion 112, the radiation regions 114, the radiation region 116, or anycombinations thereof. The plurality of openings can form a regularpattern. In one embodiment, the regular pattern can include openings andspaces between openings that appear as a rectangular grid. In anotherpattern, the regular pattern may appear as a honeycomb-like structure.In still another embodiment, the plurality of openings may form anirregular pattern.

In a particular embodiment, each of the openings of the plurality ofopenings can comprise substantially the same size and shape. In stillanother embodiment, the plurality of openings may include differentsizes, different shapes, or any combinations thereof. In one embodiment,the size (e.g., diameter or width, as seen from a top view) may be nogreater than approximately 5 microns. In another embodiment, the sizemay be no less than the lithographic limits used to form the pluralityof openings, which lithographic limits may be in a range ofapproximately 0.3 to 4 microns. Regarding shape, nearly any shape can beused, such as a circle, oval, triangle, rectangle, pentagon, anothersuitable polygon, or the like. The shape may also include differentsizes with one or more different lengths. After reading thisspecification, skilled artisans will appreciate that the openings,including depth, size and shape, and pattern of the openings, can bedesigned to meet the needs or desires for a particular application.

The density of the openings within the insulating layer 18 can affectthe flow of a subsequently-deposited liquid composition. For example, asthe density of openings within the insulating layer increases, thelateral flow of the liquid composition decreases. In one embodimentwhere lateral flow is desired, no openings or a relatively low densitymay be used. In another embodiment where lateral flow is not desired, arelatively higher density of openings may be used. In a particularembodiment, different densities of openings may be used to allowdifferent lateral flows of the liquid composition for different regions.

In one embodiment, during processing, the insulating layer 18 andopenings can overlie substantially all of the first electrode 14, 16 orboth. In another embodiment, a portion of the insulating layer 18 can beremoved to expose substantially all of the first electrode 14, or both16. In such an embodiment, each of the first electrodes 14 and 16 canlie substantially exposed within a single opening of the plurality ofopenings. In another embodiment (described later in this specification),an opening of the plurality of openings can be a channel. The channelcan help control liquid flow along the surface of the workpiece 10. Achannel can be characterized by a width in a particular embodiment,wherein the channel is an opening with a length at least 3 times itswidth. In a particular embodiment, the channel changes direction atleast once along the length. The change of direction may be in the forma sharp bend with at least one corner or as a continuous curve. Thus, achannel may or may not have a length lying along a straight line.

4. Formation of Organic Layer(s)

An organic layer can be formed over the first electrodes 14 and 16 andthe substrate 12. The organic layer may include one or more layers. Forexample, the organic layer can include an organic active layer, a bufferlayer, an electron-injection layer, an electron-transport layer, anelectron-blocking layer, a hole-injection layer, a hole-transport layer,or a hole-blocking layer, or any combinations thereof. In oneembodiment, the organic layer may include a first organic layer andorganic active layers.

Any individual or combination of layers within the organic layer can beformed by a conventional or proprietary technique, including spincoating, casting, vapor depositing (chemical or physical), printing (inkjet printing, screen printing, solution dispensing (dispensing theliquid composition in strips or other predetermined geometric shapes orpatterns, as seen from a plan view), or any combinations thereof), otherdepositing technique, or any combinations thereof for appropriatematerials as described below. Any individual or combination of layerswithin the organic layer may be cured after deposition.

As illustrated in FIGS. 3 and 4, in an embodiment, an organic layer withone or more layers can be formed over and within openings of layer 18.FIG. 4 includes an enlarged portion of the workpiece 10 at a region asillustrated by the dashed circle 4 in FIG. 3. The organic layer caninclude a first organic layer 32. The first organic layer 32 can beformed by one or more embodiments previously described for formingorganic layers. In one embodiment, the first organic layer 32 mayinclude a conventional or proprietary material that is suitable for usein a buffer layer, as used in an OLED display. In another embodiment,the thickness of the first organic layer 32, after formation iscompleted, may have a thickness in a range of approximately 50 nm toapproximately 300 nm, as measured over the substrate 12 at a locationspaced apart from the first electrode 14. In still another embodiment,the first organic layer 32 may be thinner or thicker than the rangerecited above.

The first organic layer 32 can partially fill holes within theinsulating layer 18 as illustrated in FIG. 4. The thickness of the firstorganic layer 32 may be thinner along walls of the holes within theinsulating layer 18. While the shape of the holes within the insulatinglayer 18 does not change, the openings are now determined at least inpart by the topology of the first organic layer 32. In other words, theholes within the insulating layer 18 are partially filled, and theopenings overlie the first organic layer 32 and extend into the holeswithin the insulating layer 18. In one embodiment, one or more holes inthe insulating layer 18 can be used to electrically connect the firstorganic layer 32 to one or more features below the insulating layer 18.For example, the organic layer 32 can be electrically connected to thefirst electrode 14 or 16 through one or more holes in the insulatinglayer 18.

The first organic layer 32 can be selectively formed over the substrate12. In one embodiment, the first organic layer 32 is conductive and maybe formed over the first electrode 14 and the first electrode 16. Withinthe insulating region 112 the first organic layer 32 may bediscontinuous, so that the first electrode 14 is not electricallyconnected to the first electrode 16. In another embodiment, the firstorganic layer 32 may be deposited over substantially all of theworkpiece 10 and patterned using a conventional of proprietarylithographic technique. In still another embodiment, the first organiclayer 32 may not be conductive and may be formed over substantially allof the substrate 12, including substantially all of the insulatingregion 112.

The organic layer can include an optional organic layer 52, asillustrated in FIGS. 5 and 6, that can be formed over the first organiclayer 32. FIG. 6 includes an enlarged portion of the workpiece 10 at aregion as illustrated by the dashed circle 6 in FIG. 5. In oneembodiment, the optional organic layer 52 can act as a hole-injectionlayer, a hole-transport layer, or an electron-blocking layer. Theoptional organic layer 52 may be formed by a conventional or proprietarytechnique used for a hole-injection, hole-transport, orelectron-blocking layer. The technique used for the formation of theoptional organic layer 52 may be the same or different from that used toform the first organic layer 32. In one particular embodiment, theoptional organic layer 52 may be applied with a spin-on process. Afterformation, the optional organic layer 52 can have a thickness in a rangeof 5 nm to 300 nm.

The optional organic layer 52 can overlie the first organic layer 32. Ina particular embodiment, the optional organic layer 52 can contact thesubstrate 12 within at least one opening of the insulating layer 18within the insulating region 112 at a location where the first organiclayer 32 is not present. The combined thickness of the first andoptional organic layers 32 and 52 within an opening within theinsulating layer 18 can be less than the depth of the opening. At thispoint in the process, the openings corresponding to the holes within theinsulating layer 18 are now determined at least in part by the topologyof the optional organic layer 52. In other words, the holes within theinsulating layer 18 are partially filled, and the openings overlie theoptional organic layer 52 and extend into the holes within theinsulating layer 18.

As illustrated in FIGS. 7 and 8, spectral layers 74 and 76 can be formedover the first electrodes 14 and 16, respectively. FIG. 8 includes anenlarged portion of the workpiece 10 at a region as illustrated by thedashed circle 8 in FIG. 7. The spectral layers 74 and 76 can include oneor more spectral materials. The organic layer 82 includes the firstorganic layer 32, optional organic layer 52, and spectral layers 74 and76.

The spectral layers 74 and 76 can be formed over the first electrodes 14and 16, respectively, within the radiation regions 114 and 116,respectively. The spectral layers 74 and 76 can be deposited usingliquid compositions and a selectively depositing apparatus (e.g.,ink-jet printing apparatus, continuous printing apparatus, etc.)previously described.

In a particular embodiment, illustrated from a top view in FIG. 9, acontinuous printing process can be used to form liquid compositions forthe spectral layers 74 and 76. In FIG. 9, and elsewhere in thisdocument, some layers have not been illustrated in top-viewillustrations to better indicate the relative positions of otherfeatures.

During the placement of the liquid composition for the spectral layer74, the liquid composition can have a first portion within the radiationregion 114 and a second portion that lies within the insulating region112, wherein the second portion substantially fills one or more openingsof the plurality of openings. Similarly, the liquid composition for thespectral layer 76 can have a first portion within the radiation region116 and a second portion within the insulating region 112, wherein thesecond portion substantially fills one or more openings within theplurality of openings. One or more openings of the insulating layer 18within the radiation region 114 can be substantially filled by theliquid composition for the spectral layer 74, and one or more openingsof the insulating layer 18 within the radiation regions 116 can besubstantially filled by the liquid composition for the spectral layer76.

The liquid composition can be greater than 95% liquid medium by weight.In one embodiment, the depth of the liquid composition for spectrallayer 74, 76, or both, at the time of placement can be in a range ofapproximately 1 micron to approximately 10 microns deep as measured overits corresponding radiation region, and in another embodiment may be ina range of approximately 5 microns to approximately 8 microns deep. In aparticular embodiment, the height of the liquid composition can be morethan approximately 4 times the height of the insulating layer 18.

The edges of the openings within the insulating layer 18 can providepinning points for the liquid compositions. The edges of the openingswithin the insulating layer 18 help to slow the lateral flow of theliquid compositions, thus, reducing the amount of encroachment of theliquid compositions from the radiation regions 114 and 116 into theinsulating region 112. The reduced encroachment helps to reduce thelikelihood that a spectral material from a radiation region will flow orotherwise migrate into another radiation region in which such spectralmaterial is undesired. In one embodiment, the spectral layer 74 includesa red light-emitting organic material and the spectral layer 76 includesa blue light-emitting organic material. The openings within theinsulating layer 18 help to reduce the likelihood that the redlight-emitting organic material enters into a region with the bluelight-emitting organic material, and thus can help to improve the colorcontrol within a pixel.

After the liquid medium within the liquid compositions are evaporated orotherwise substantially removed, remaining portions of the spectrallayers 74 and 76 can be at locations previously covered by therespective liquid compositions. For example, a remaining portion of thespectral layer 74 can be formed substantially lying within one or moreopenings of the insulating layer 18 within the radiation region 114, anda remaining portion of spectral layer 76 can be formed substantiallylying within one or more openings of the insulating layer 18 within theradiation region 116. In one embodiment, at least some of the remainingportions of the spectral layers 74 and 76 can substantially fill each oftheir respective openings. Another remaining portion of spectral layer74 and another remaining portion of spectral layer 76 can each liewithin one or more openings of the insulating layer 18 within theinsulating region 112. In another embodiment, at least some of theremaining portions of the spectral layers 74 and 76 can substantiallyfill each of the respective openings. In one embodiment, as illustratedin FIG. 9, a location between the spectral layers 74 and 76 can have oneor more openings within the insulating region 112 that are substantiallyvoid of the spectral layers 74 and 76.

The spectral layer 74 can include an organic active layer. Thecomposition of the spectral layer 74 can depend upon the application ofthe electronic device. In one embodiment, the spectral layer 74 is partof a radiation-emitting component. In a particular embodiment, thespectral layer 74 can include a blue light-emitting material, a greenlight-emitting material, or a red light-emitting material. The spectrallayer 76 can also be an organic active layer and in one embodiment, canbe formed for radiation at a different targeted wavelength or spectrumof wavelengths, as compared to the spectral layer 74. For amonochromatic display, spectral layer 76 may have substantially the samecomposition as spectral layer 74. In another embodiment, a spectrallayer that is substantially continuous over substrate 12 (notillustrated) can replace the spectral layers 74 and 76. In anotherembodiment, the spectral layer 74 may be used in a radiation-responsivecomponent, such as a radiation sensor, photovoltaic cell, or the like.In still another embodiment, the spectral layer 74 can act to filterradiation by either reflecting or absorbing targeted wavelengths orspectra of wavelengths and allowing other wavelengths or spectra ofwavelengths to pass.

The spectral layers 74 and 76 can include material(s) conventionallyused as organic active layers in organic electronic devices and caninclude one or more small molecule materials, one or more polymermaterials, or any combination thereof. After reading this specification,skilled artisans will be capable of selecting appropriate material(s),layer(s) or both for the spectral layer 74 or potentially other spectrallayers. In one embodiment, after formation, the spectral layer 74, 76,or any combination thereof, has a thickness in a range of approximately40 to 100 nm, and in a more specific embodiment, in a range ofapproximately 70 to 90 nm. One or more additional spectral layers (notillustrated) may be formed in a similar fashion within other radiationregions.

Although not illustrated, additional layers, such as a hole-blockinglayer, an electronic-injection layer, an electron-transport layer, orany combinations thereof may be formed over the spectral layers, such asthe spectral layer 74, the spectral layer 76, one or more other spectrallayers, or any combinations thereof. The electron-transport layer canallow electrons to be injected from the subsequently formed secondelectrode (i.e., cathode) and transferred to the spectral layers 74 and76. The hole-blocking layer, electronic-injection layer,electron-transport layer, or any combinations thereof, typically has athickness in a range of approximately 30 nm to approximately 500 nm.

In one embodiment, any one or more of the layers within the organiclayer 82 may be patterned using a conventional or proprietary techniqueto remove portions of the organic layer 82 where electrical contacts(not illustrated) are subsequently made. Typically, the electricalcontact areas are near the edge of the array or outside the array toallow peripheral circuitry to send or receive signals to or from thearray.

5. Remainder of Fabrication

A second electrode 101 is formed over the organic layer 82 asillustrated in FIG. 10. In one embodiment, the second electrode 101 canact as a cathode. An array of the electronic device can have one or morecommon cathodes, wherein each common cathode is shared by a plurality ofelectronic components. In still another embodiment (not illustrated),the second electrode 101 can include one cathode for each electronicradiation-emitting or radiation-responsive component within the array.

In one embodiment, the second electrode 101 can include a low workfunction layer and a conductive layer that helps to provide goodconductivity. The low work function layer can include a Group 1 metal(e. g., Li, Cs, etc.), a Group 2 (alkaline earth) metal, a rare earthmetal, including the lanthanides, the actinides, a corresponding oxideor halogenide (such as LiF, Li₂O, BaO, etc.), an alloy including any ofthe foregoing metals, or any combination thereof. A conductive polymerwith a low work function may also be used. The conductive layer mayinclude nearly any conductive material, including those previouslydescribed with respect to the electrodes 14 and 16. The conductive layeris used primarily for its ability to allow current to flow while keepingresistance relatively low. An exemplary material for the conductivelayer includes aluminum, silver, copper, or any combination thereof.

The second electrode 101 can be formed using any one or more of theformation techniques described with respect to the electrode 14. In manyapplications, the thickness of the second electrode 101 may be in arange of approximately 5 nm to approximately 500 nm. If radiation is notto be transmitted through second electrode 101, the upper limit on thethickness may be greater than 500 nm.

Other circuitry, not illustrated, may be formed using any number of thepreviously described or additional layers. Although not illustrated,additional insulating layer(s) and interconnect level(s) may be formedto allow for circuitry in peripheral areas (not illustrated) that maylie outside the array. Such circuitry may include row or columndecoders, strobes (e.g., row array strobe, column array strobe, or thelike), sense amplifiers, or any combination thereof.

A lid 107 with a desiccant 105 is attached to the substrate 12 atlocations (not illustrated) outside the array to form a substantiallycompleted electronic device. A gap 103 may or may not lie between thesecond electrode 101 and the desiccant 105. The materials used for thelid and desiccant and the attaching process are conventional orproprietary. The lid 107 typically lies on a side of the electronicdevice opposite the user side of the electronic device. Still, ifdesired, radiation may be transmitted through the lid 52 instead of orin conjunction with the substrate 12. If so, the lid 107 and thedesiccant 105 can be designed to allow sufficient radiation to passthrough.

In other embodiments, the first and second electrodes can be reversed.In this embodiment, the second electrode 101 would lie closer to theuser side of the substrate 12, as compared to the first electrodes 14and 16. The second electrode 101 could include a plurality of secondelectrodes that are each connected to control circuits (notillustrated). Also, a common first electrode could replace the firstelectrodes 14 and 16. In still another alternative embodiment, thecontrol circuits may be connected to one type of electrode that liesfarther from the substrate 12 as compared to the other type ofelectrode.

6. Alternative Embodiments

FIG. 11 includes an illustration of an alternative embodiment that isformed in a manner similar to the process described in Section 3 aboveexcept that portions of the insulating layer 18 overlying the firstelectrodes 14 and 16 have been removed such that there is a singleopening overlying each of the first electrodes 14 and 16. Processing canproceed as previously described. One or more openings within theinsulating layer 18 can still provide a pinning point for a liquidcomposition.

FIG. 12 includes an illustration of another alternative embodiment thatis formed in a manner similar to the process described in Section 3above except that in addition to the openings over the first electrodes14 and 16, as illustrated in FIG. 11, channels 121 have been formed bypatterning portions of the insulating layer 18 between adjacentelectrodes 14 along the intended flow direction of the continuousprinting process. Portions of the substrate 12 are exposed along bottomsof the channels 121. Such a pattern can help improve the flow of theliquid compositions for the spectral layers. In one embodiment, theportions of the insulating layer 18 lying between the electrodes 14 canbe removed entirely such that a continuous opening is formed along theintended path of a continuous printing process.

FIG. 13 includes an illustration of another alternative embodiment thatis formed in a manner similar to the process described in Section 3above except that the insulating layer 18 and the plurality of openingstherein are formed prior to formation of the first electrode 14. In aparticular embodiment, the first organic layer 32 can help toelectrically connect different portions of the first electrode 14.

In another embodiment (not illustrated), the insulating layer 18 is notformed and the openings are formed within a portion of the substrate 12.The depth, size, shape, and spacing of the openings extending into thesubstrate 12 can be in a range as previously described with respect tothe openings as initially formed within the insulating layer 18. In aneven more particular embodiment, the openings in substrate 12 have asubstantially uniform depth.

In another embodiment (not illustrated), one or more additional layerswith significantly different refractive index(ices) from insulatinglayer 18 can be formed within one or more openings of the plurality ofopenings. Such a structure can help to reduce the wave guiding effect ofradiation within the electronic device. In one embodiment, a portion ofsuch an additional layer on a sidewall of an opening could affect theamount of light trapped within insulating layer 18. For example, ifinsulating layer 18 includes silicon dioxide (η of approximately 1.45),the additional layer could include silicon nitride (η of approximately2.0), polysilicon (η of approximately 3.0), a fluoropolymer (η ofapproximately 1.6 to 1.8), or any combinations thereof. As thedifference in refractive indices between the insulating layer 18 and theone or more optional layers increases, the ability to redirect theradiation toward the user surface improves.

In another embodiment, the one or more additional layers may include aportion along a bottom of an opening and act as a micro lens. Theportion can gather light and affect how it projects to the user surfacefor a radiation-emitting component. In another embodiment, the portioncan help redirect ambient radiation from outside the electronic deviceto a radiation-responsive layer (e.g., an organic active layer) within aradiation-responsive component. In a particular embodiment, refractiveindex(ices) of the one or more additional layers may be the same ordifferent as compared to the insulating layer 18.

With respect to process integration using the one or more additionallayers, the one or more additional layers with some embodiments may beformed using additional processing, such as removing a portion of thematerial from along a bottom of the opening so that the opening canserve as an electrical connection between layers. For example, wheninsulating layer 18 overlies the anode, an additional patterning andetch operation may be used to remove a portion of the one or moreadditional layers to allow electrical connection between the firstorganic layer 32 and each of the first electrodes 14 and 16. Afterreading this specification, skilled artisans will appreciate that theone or more additional layers can be used with respect to otherembodiments, some of which are described in this specification.

FIG. 14 includes an illustration of a top view of another alternateembodiment of in which a layer has different regions. The region 141includes a first plurality of openings and the region 143 includes asecond plurality of openings. The first plurality of openings withinregion 141 may be at a higher opening density as compared to the secondplurality of openings within 143. A liquid composition deposited overthe layer may preferentially flow within the region 143 because of thelower density of openings and fewer pinning points, as compared to theregion 141. The ability of a liquid composition to spread across an areawith fewer pinning points can be less restrained than flow across anarea with more pinning points. In another embodiment, the density ofopenings within the regions 141 and 143 could be reversed to alloweasier flow within the region 141 as opposed to the region 141. In stillanother embodiment, the region 141 can include a density of openings,and the region 143 can include a channel that includes more than onechange in direction along the length of the channel.

In one embodiment, the plurality of openings can form a regular patternsuch as a plurality of openings in a rectangular grid as illustrated inFIG.15. Continuous printing along a direction of the grid can formprinted lines at locations 151 and 153. The edges of lines printed inthis manner can tend to align with rows of the grid. For example, atlocation 151, a substantially straight line with substantially straightedges can be printed. In one embodiment, the right-hand edge of the lineis substantially aligned along a first row 150 of openings. In anotherexample, at location 153, another line is also printed that issubstantially oriented along a vertical direction in FIG. 15. However,the left-hand edge of that line is not straight, as a portion of theleft-hand edge can be aligned substantially along a second row 152 ofthe openings within the grid and other portions can be alignedsubstantially along other rows of openings within the grid such as athird row 154 of openings or a fourth row 156 of openings. After readingthis specification, skilled artisans will appreciate that other shapesof openings (e.g., circles) may be used instead of or in conjunctionwith squares as illustrated in FIG. 15.

In still another embodiment, the openings within a layer may be in theform of a roughened surface. Instead of using a patterning layer, anabrasion technique (e.g., “sandblasting”) can be used to roughen thesurface of the substrate 12 to produce irregularly shaped openings. Suchopenings can still help to reduce intended lateral flows of liquidcompositions. In still another embodiment, a layer may be deposited andappear as a roughened layer. For example, a vapor phase deposition canbe operated such that gas phase nucleation occurs before reaching anddepositing onto a surface of the workpiece 10. The process can formclusters of material that may be discontinuous in at least some regionsor provide an irregular surface (similar to a roughened surface aspreviously described).

The concepts described herein can be used to affect layer(s) that arenot designed to emit, respond, or filter radiation. Such an applicationmay be used to form a circuit element including a transistor, aresistor, a capacitor, a diode or any combination thereof. Note that anyof these electronic components may be used in logic, amplifying, oranother circuit and may or may not be used for their radiation-relatedproperties.

7. Advantages

After reading this specification, skilled artisans will appreciateplacement of liquid compositions can be more accurately controlled bycreating a plurality of openings in a surface prior to applying theliquid composition. This can allow the formation of displays withsmaller than previously possible pixel size without the need to buy newequipment or create new formulations of liquid compositions. Forexample, a liquid composition can be printed to a width as narrow asapproximately 40 microns when using the insulating layer 18 with theopenings. If the insulating layer 18 with the openings is not used, thesame liquid composition may not be printed to a width narrower thanapproximately 80 microns. Smaller widths allow for a higher pixeldensity and better resolution within a display.

Use of this process can also reduce the need for banks or other physicalcontainment structures for the liquid composition during the depositionprocess. Fluorination or other activities or materials to reduce surfaceenergy may also be eliminated. Still further, a receiving layer for theliquid composition is also not required. Elimination of banks or othercontainment structures, fluorination or other activities or materials, areceiving layer, or any combination thereof reduces the number ofmanufacturing operations. Still, any of the banks or other containmentstructures, fluorination or other activities or materials, a receivinglayer, or any combination thereof can be used if desired.

In some embodiments, insulating layer 18 can help improve the radiationemission from or collection within the electronic device. Such animprovement can increase the amount of radiation reaching the usersurface of the electronic device or the amount of radiation received byone or more electronic components within the electronic device withoutchanging the electronic operating parameters of the electronic device(e.g., voltage, current, etc.).

EXAMPLE

The following specific example is meant to illustrate and not limit thescope of the invention. This example demonstrates that the appropriatemanipulation of one or more physical properties of an insulating layerand a liquid composition can provide an electronic component in anelectronic device without the need for a bank or well structure. Thedescription below refers to FIG. 16.

Electronic components are fabricated to include the following structure:ITO or IZO (first electrodes or anodes)/ silicon dioxide or siliconnitride layer including plurality of openings/buffer layer/organicactive layer /second electrode (cathode). The substrate is 30 mm×30 mm(nominal) ITO coated glass. The charge-transport layer is a PEDOTmaterial (BAYTRON-P™, Bayer AG, Germany). The organic active layerincludes a red light-emitting polyfluorene material (a material capableof emitting red light). A thin continuous SiN or SiO₂ layer 162 of lessthan 1000 nm thickness is deposited overlying the first electrodes andpatterned using photolithography to form a plurality of substantiallysquare via openings 164 of approximately 10 microns×approximately 10microns in a rectilinear pattern. Organic active layer 166 is printedoverlying a portion of the openings 164 and extending onto the SiN orSiO₂ layer using the same conditions for printing. The ratio of theprinted line with is measured at approximately 40 microns over the areawith via openings and approximately 80 microns over an area without viaopenings or a well structure. After reading this specification, skilledartisans will appreciate that other shapes of openings (e.g., circles,not illustrated) may be used instead of or in conjunction with thesquares illustrated in FIG. 16.

Note that not all of the activities described above in the generaldescription or the examples are required, that a portion of a specificactivity may not be required, and one or more that further activitiesmay be performed in addition to those described. Still further, theorder in which activities are listed are not necessarily the order inwhich they are performed. After reading this specification, skilledartisans will be capable of determining what activities can be used fortheir specific needs or desires.

In the foregoing specification, the invention has been described withreference to specific embodiments. However, one of ordinary skill in theart appreciates that one or more modifications or one or more otherchanges can be made without departing from the scope of the invention asset forth in the claims below. Accordingly, the specification andfigures are to be regarded in an illustrative rather than a restrictivesense and any and all such modifications and other changes are intendedto be included within the scope of invention.

Any one or more benefits, one or more other advantages, one or moresolutions to one or more, problems, or any combination thereof has beendescribed above with regard to one or more specific embodiments.However, the benefit(s), advantage(s), solution(s) to problem(s), or anyelement(s) that may cause any benefit, advantage, or solution to occuror become more pronounced is not to be construed as a critical,required, or essential feature or element of any or all the claims.

It is to be appreciated that certain features of the invention whichare, for clarity, described above and below in the context of separateembodiments, may also be provided in combination in a single embodiment.Conversely, various features of the invention that are, for brevity,described in the context of a single embodiment, may also be providedseparately or in any subcombination. Further, reference to values statedin ranges include each and every value within that range.

1. An electronic device, comprising: a first radiation region; a secondradiation region spaced apart from the first radiation region; aninsulating region having a first side and a second side opposite thefirst side, wherein: the first radiation region lies immediatelyadjacent to the first side; the second radiation region lies immediatelyadjacent to the second side; within the insulating region, no otherradiation region lies between the first and second radiation regions;and the insulating region includes an insulating layer that includes aplurality of openings; and a first spectral layer including a firstportion and a second portion, wherein: the first portion of the firstspectral layer lies within the first radiation region; the secondportion of the first spectral layer lies within a first opening of theinsulating layer, wherein the plurality of openings includes the firstopening; and from a plan view, the first spectral layer overlies only aportion of the insulating layer within the insulating region.
 2. Theelectronic device of claim 1, wherein the plurality of openings forms aregular pattern.
 3. The electronic device of claim 1, wherein eachopening within the plurality of openings comprises substantially a samesize, a same shape, or any combination thereof.
 4. The electronic deviceof claim 1, wherein the first radiation region further comprises aportion of the insulating layer.
 5. The electronic device of claim 4,wherein within the first radiation region, at least a part of the firstportion of the first spectral layer lies within a second opening of theplurality of openings.
 6. The electronic device of claim 5, wherein thefirst radiation region further includes a conductive member overlyingthe insulating layer.
 7. The electronic device of claim 5, wherein thefirst radiation region further includes a conductive member, and whereinthe insulating layer overlies the conductive member.
 8. The electronicdevice of claim 1, wherein a third opening of the plurality of openingscomprises a channel.
 9. The electronic device of claim 8, wherein, froma plan view, the channel changes direction at least once along a lengthof the channel.
 10. The electronic device of claim 1, wherein the firstspectral layer comprises an organic active layer.
 11. The electronicdevice of claim 1, further comprising a second spectral layer includinga first portion and a second portion, wherein: the first portion of thesecond spectral layer lies within the second radiation region; thesecond portion of the second spectral layer lies within a second openingof the insulating layer, wherein the plurality of openings includes thesecond opening; and from a plan view, the second spectral layer overliesonly a portion of the insulating layer within the insulating region. 12.The process of claim 1, wherein the insulating layer comprises an oxide,a nitride, or any combination thereof.
 13. A process for forming anelectronic device, the process comprising: patterning an insulatinglayer, wherein; the patterned insulating layer defines a plurality ofopenings within the insulating layer; and a first opening and a secondopening of the plurality of openings lie within the insulating region,the insulating region having a first side and a second side opposite thefirst side, wherein: a first radiation region lies immediately adjacentto the first side; a second radiation region lies immediately adjacentto the second side; and within the insulating region, no other radiationregion lies between the first and the second radiation regions; forminga first liquid composition at a first location overlying a substrate,wherein the first liquid composition includes a first portion and asecond portion, wherein: the first portion of the first liquidcomposition lies within the first radiation region; the second portionof the first liquid composition substantially fills the first opening ofthe plurality of openings; and substantially none of the first liquidcomposition is formed within the second opening of the plurality ofopenings.
 14. The process of claim 13, wherein during formation of thefirst liquid composition, a thickness of the first liquid compositionlayer is at least four times a depth of the first opening.
 15. Theprocess of claim 13, further comprising forming a second liquidcomposition at a second location overlying the substrate, such that thesecond liquid composition substantially fills a third opening of theplurality of openings.
 16. The process of claim 15, wherein a portion ofthe patterned insulating layer comprising the second opening liesbetween the first location and the second location.
 17. The process ofclaim 16, wherein substantially none of the second liquid composition isformed within the second opening.
 18. The process of claim 13, whereinforming the first liquid composition comprises continuously printing thefirst liquid composition.
 19. The process of claim 18, wherein the firstliquid composition includes a spectral material.
 20. The process ofclaim 13, wherein patterning the insulating layer further comprisesforming at least one opening extending through the insulating layer.